They came from Germany, Holland, France, Italy, Sweeden, Canada, Australia, the US and of course London town. All 190 packed into the Paramount club on the thirty-first floor of the centre point building - there to discuss the exchange eco-system and the future of media optimisation in Europe. The afternoon event was split into three areas: sell-side, data and buy-side. Each had a key-note followed by a Q&A session. Ben Barokas, Co-Founder & Chief Revenue Officer, Admeld, opened up proceeding with an in-depth presention on how the European sell-side was developing. The presentation started with an excellent overview of how the ad network market has grown since 1994 - and the difficulty publishers encountered when managing and monetisining non-premium inventory. There was lots of focus on RTB, which is now generating significant price lift for participating publishers. Ben walked us through some Admeld stats on the growth of RTB in Europe. Admeld is now seeing 20 billion monthly bid requests, and growth in European RTB is now outpacing that of the US. The following benefits of impression-level buying were flagged by Ben as good reasons for publishers to open up their inventory to real-time buyers: firstly it provides a direct line to new buyers, budgets and higher CPMs; it provides the ability to sell the way buyers are buying; and lastly it gives impression-level control and tranparency.

Following Ben's presentation, we had three sell-side experts give some perspective and analysis on trends affecting publishers. Richard Foster, Digital Director of Future Publishing, Damon Reeve, CEO of Unanimis, and Jay Stevens, VP & GM, International at the Rubicon Project were on hand to provide some excellent debate. Juicy issues like sales cannibalisation, "data leakage" and ad networks were discussed in depth. Publishers in the room voiced concerns on inventoy commoditisation and the possibility of downward pressure on CPM pricing if inventory was opened up to real-time trading. Real concerns from the people who actually provide the market with ad impressions in the first place. Let's not forget that. The "conflict of interest" issue was also discussed at length - namely can you act on the buy-side and sell-side and maintain the commercial interests of publishers. All three panelists agreed that at some stage ad tech vendors would have to position themselves on the buy or sell side. When? Nobody was sure - or would hazard a guess.

Next up was the data section. Konrad Feldman took the stage and presented a sublime presentation on the growth of the European data economy - and the infrastructure required to properly trade data. Konrad pointed out that the way data is being currently leveraged in the display market could work in other media channels - most notably the big money TV ad market. It was top-tier stuff, and the man's presentation is hotly in demanded (incidentally, I will see if it's possible to publish all presentations in the coming weeks). If the presentation was in-depth, then the data panel could only be described as beefy. The panel was moderated by Paul Silver, Associate Director at Starcom Mediavest Group. He was joined by some pretty heavyweight expertise, including Stuart Colman, UK Managing Director, AudienceScience, Arnaud Caplier , Co-Founder, Datvantage, and Michael Stephanblome, CEO and Co Founder, AdJug.

This was a wide-ranging panel, and given the growing importance of data, one of the more livelier discussions of the day. Data pricing, portability and data ownership dominated proceedings. There was lots of interaction from the floor. Publishers who are now becoming ever more active in the data market were asking the pertinent questions of the session. Louisa Wong, Head of Network Advertising at BSkyB, raised the issue of data pricing - and how segments should be valued. This sparked some interesting to-ing and fro-ing from floor and panel. The crux of the data-pricing problem is that there is no way to benchmark pricing. Do you work on a CPM basis or a percentage of campaign lift? This could have bubbled on for the entire afternoon - and probably deserves an event of its own. The discussion then turn to privacy. And I'll be honest here, privacy is a beast of a subject. Wisely Paul left it to last to let the panel and audience loose on the subject of privacy. This is a thorny and complicated issue in Europe - due mainly to the EU's clumsy meddling in the matter. Opt-ins for behavioural tracking is the favoured option of the EU at the minute - but as one panelist pointed out, implementing a heavy opt-in would put the likes of Google in an even stronger commercial position. And so the issue of European user privacy was discussed and remains unresolved.

The buy-side was the final session of the day. Vivaki's Curt Hecht and Marco Bertozzi presented the keynote on the rise of ad trading in Europe and how Vivaki is developing its exchange strategy to deliver real value for its cleints. In a wide ranging presentation, both discussed the key drivers of automated ad trading, namely targeting, transparency, data leverage, pricing and efficiency. Vivaki provided some numbers on volumes traded and the amount of campaigns they have run through the automated channel. So far they have traded more than 12 billion impressions, and completed over three thousand campaign across exchange inventory. Curt also discussed how the move to automated ad trading would require an evolution of the current agency model, in terms of skill sets and technology capabilities.

We finished the day with the buy-side Q&A. Joining me on stage were Martin Kelly from Infectious Media, Tanzil Bukhrani from Google and Mike Nolet form AppNexus. I have to say I really enjoyed moderating this panel. Lots of great discussion and banter from the audience and the panel. The hot topics included disintermediation, fragmentation and buy-side ad technology. The one thing to emerge form the debate was that the death of the ad network has been greatly exagerated. It's simply evolving - and still has an important role to play. Ad networks are built for aggregation, targeting, and have been developing technology for ten years to deliver value for agency clients. Will the agencies be able to match ad nets for scale and indeed performance? In the shot term, probably not. But as the eco-system grows, there was an agreement that holding agencies would become more skilled at trading inventory. And would probably put the squeeze on ad networks. I did ask the question about whether or not ad nets should go after the client direct relationship - given that they might be able to offer price flexibility and outperform holding agencies. The consensus in the room was that despite the move to DSP trading, ad networks would still be heavily involved int he media plan in the coming years.

And thus ended the first Ad Trading Summit. It was the first event of its kind to bring the participants of the European eco-system under one roof to discuss this emerging market. I would like to thank all the sponsors - Vivaki, Admeld, AppNexus, Adfonic and Quantcast - for supporting the event. And I want to thank all the attendees. Great to see such enthusiasm and excitement form all there. Here's to next year. Looking forward to it already.